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| The effects of Global Warming on people, our environment and all other living beings cannot be underestimated. The global climate change is increasingly recognized as the key threat to the continued development – and even survival - of mankind. History provides evidence of human societies that disappeared because of drastic changes in the climate. Though the importance of climate change looms at large, it is far less important for governments and individuals when compared to the need for daily supply of energy, the problems of poverty, infectious diseases, extinction of species and even war, nuclear weapons or biological warfare. The consequences of Global Warming pose real dangers and responding to such dangers presents tremendous political and economic challenges to every nation. |
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Pre-historic Climate Change & the Current Interglacial |
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Our understanding of climate variability has increased greatly over the past few decades because the climate record since the last glaciation has been developed through studying sediments from melting episodes in ice sheets and ice caps, and pollen, dust, and isotopic records in ice caps and lake and river sediments.
During the last 2.6 million years, the duration of the current Ice Age, there have been 104 major fluctuations between global cold and global warmth. Each of the major fluctuations was itself complex, encompassing ‘minor’ changes of up to 5 degrees centigrade in average annual temperature. As temperatures rose and fell, so did global sea level, by up to 130 meters. These changes did not lead to catastrophic global extinctions of the earth’s biota. The extensive animal and plant communities of the past, undisrupted by human development, could adapt to the changes by migrating, or by shrinking or expanding populations. In shrinking animal populations, of course, there is an excess of deaths over births, by starvation or predation. Our current human population, faced with comparable climate change, will have a similar choice, and there is now little room for migration.
Human development has coincided with one of the relatively infrequent episodes of prolonged climate stability, of a little over 10,000 years since the end of the last glaciation. This episode is the latest of a series of interglacial phases which, in the last half million years, have occurred at intervals of roughly 100,000 years. It has been commonly thought that we are at the tail-end of this warm climate phase, and that feeling sharpened in the late 1990’s when new data from Antarctic ice cores showed that the previous three warm phases each lasted between 6000 and 9000 years. Thus, given a similar trend, the ice-sheets would have returned to cover Europe during the ancient Egyptian or Greek civilizations, and the trend of human history would have been immeasurably different.
The longest Antarctic ice-core record yet obtained shows that the warm phase before that, a little less than half a million years ago, lasted some 30,000 years. That long interglacial episode is thought to be the best model for our current warm phase, because of the similarity of the earth’s alignment vis-à-vis the sun’s rays. On these grounds, therefore, even without human intervention, another 20 000 years of warmth may be expected.
As regards the greenhouse gases carbon dioxide and methane, the link of these to climate is firm. The ice-cores not only preserve a detailed and reproducible record of global temperature but also contain a record of atmospheric composition, now going back three-quarters of a million years, as bubbles of gas trapped in the ice layers. As temperatures rose and fell, so did the levels of these gases in the atmosphere. |
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History of Global Warming |
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| From ancient times people suspected that human activity could change the climate. For example, in the 19th century many Americans believed that cutting down forests brought more rainfall to a region. The discovery of ice ages in the distant past proved that climate could change all by itself, and radically. But what caused these changes — was it variations in the heat of the Sun? Volcanoes erupting clouds of smoke? The raising and lowering of mountain ranges, which diverted wind patterns and ocean currents? Or could it be changes in the composition of the air itself? |
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The idea that some gases in the atmosphere trap heat was first proposed Fourier in 1824 and was first investigated quantitatively by Swedish scientist Svante Arrhenius in 1896. Svante Arrhenius (1859-1927) was the first to claim that fossil fuel combustion may eventually result in enhanced global warming and proposed a relation between atmospheric carbon dioxide concentrations and temperature. Arrhenius suggested a doubling of the CO2 concentration would lead to a 5oC temperature rise. He and Thomas Chamberlin calculated that human activities could warm the earth by adding carbon dioxide to the atmosphere.
However, this was soon forgotten and it was thought than human influences were insignificant compared to natural forces, such as solar activity and ocean circulation. It was also believed that the oceans were such great carbon sinks that they would automatically cancel out our pollution.
In the 1940s it was proven that increasing the amount of atmospheric carbon dioxide resulted in more absorption of infrared radiation. And in 1955 Gilbert Plass concluded that adding more carbon dioxide to the atmosphere would intercept infrared radiation that is otherwise lost to space, warming the earth.
In the late 1950's and early 1960's Charles Keeling used the most modern technologies available to produce concentration curves for atmospheric CO2 in Antarctica and Mauna Loa. These curves have become one of the major icons of global warming. The curves showed a downward trend of global annual temperature from the 1940's to the 1970's. At the same time ocean sediment research showed that there had been no less than 32 cold-warm cycles in the last 2,5 million years, rather than only 4. Therefore, fear began to develop that a new ice age might be near. The media and many scientists ignored scientific data of the 1950's and 1960's in favor of global cooling.
In the 1980's, finally, the global annual mean temperature curve started to rise and the theory of an upcoming new ice age was challenged. Later in the decade, the curve began to increase so steeply that the global warming theory began to win terrain fast. Environmental NGOs started to advocate global environmental protection to prevent further global warming while simultaneously it became a hot news topic as the media gained more interest in global warming.
Stephen Schneider had first predicted global warming in 1976 and this made him one of the world's leading global warming experts. In 1988 it was finally acknowledged that climate was warmer than any period since 1880. The greenhouse effect theory was named and Intergovernmental Panel on Climate Change (IPCC) was founded by the United Nations Environmental Program and the World Meteorological Organization. |
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Greenhouse Effect & Global Warming |
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Greenhouse effect is a natural process that maintains the Earth’s temperature levels conducive to life. The Earth absorbs heat from the Sun and radiates it back to space in the form of infrared radiations. The atmosphere has a natural supply of greenhouse gases, namely carbon dioxide, methane, nitrous oxide, water vapor and ozone, which constitute approximately 1% of the atmosphere. These gases reflect the heat back to Earth and this in turn maintains the average temperature. In absence of these greenhouse gases, the Earth would be a frozen, uninhabitable planet!
The issue at large is mankind’s role in enhancing the greenhouse effect that is contributing to the unnatural, untimely global warming. |
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Global warming is the increase in the average temperature of the surface air and the oceans. Pre-Industrial revolution, the levels of greenhouse gases released into the atmosphere were more or less in balance with what could be stored on Earth. Natural emissions of heat-trapping gases matched what could be absorbed in natural sinks. Starting mid-1700s, burning of fossil fuels to run our cars, trucks, factories, planes and power plants began emitting large amounts of greenhouse gases adding to the natural supply. The gases are building up beyond the Earth's capacity to remove them and, in effect, are creating an extra-thick heat blanket around the Earth. The result – the Earth has become hotter by one degree Fahrenheit over the past century and has heated up more intensely in the past two decades. Today, the amount of carbon dioxide, the chief global warming pollutant, in the atmosphere has increased to 31% above the pre-industrial levels. There is more CO2 in the atmosphere now than at any time in the last 650,000 years!
One theory of global warming suggests that Earth naturally changes its own atmosphere and that this has been occurring for centuries. At one time the earth was covered in ice, then it was hot and humid and eventually became what it is today, a combination of many different climates. And since the change in climate is a natural occurrence, these changes are not affected by man, the industrial age or by the pollutants that humans dump into the environment daily.
The other theory is that everything we do has a direct cause and effect on global warming. Our actions and activities have increased global temperatures that have caused the sea levels to rise and have changed precipitation rates causing floods and droughts around the world. In addition, changes in weather patterns and the increase of violent hurricanes and tornados are also directly linked to global warming. |
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The Dangers of Global Warming |
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Is global warming already happening?
The IPCC concluded in its Third Assessment Report, "An increasing body of observations gives a collective picture of a warming world and other changes in the climate system." |
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Examples of observed climatic changes
- Increase in global average surface temperature of about 1°F in the 20th century.
- Decrease of snow cover and sea ice extent and the retreat of mountain glaciers in the latter half of the 20th century.
- Rise in global average sea level and the increase in ocean water temperatures.
- Likely increase in average precipitation over the middle and high latitudes of the Northern Hemisphere, and over tropical land areas.
- Increase in the frequency of extreme precipitation events in some regions of the world.
Examples of observed physical and ecological changes
- Thawing of permafrost.
- Lengthening of the growing season in middle and high latitudes.
- Poleward and upward shift of plant and animal ranges.
- Decline of some plant and animal species.
- Earlier flowering of trees.
- Earlier emergence of insects.
- Earlier egg-laying in birds.
We have already seen some of the results from global warming—more hurricanes, more frequently and more violent. Increasing global temperatures will cause sea level to rise, and is expected to increase the intensity of extreme weather events and to change the amount and pattern of precipitation. Other effects of global warming include changes in agricultural yields, glacier retreat, species extinctions, and increases in the ranges of disease vectors. There may be dramatic changes to the growing season and a shift in where crops can be grown, the glaciers may start to melt causing a rise in sea levels that will flood coastal cities, some species will go extinct and some diseases may come back or increase in volume. It is believed that global warming will cause more tsunamis, earthquakes, forest fires, and even heat waves in places where heat waves are not a norm. Consequences such as the shifts in temperature and rainfall may create dustbowls and famines. |
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Health |
Spreading of disease
In places experiencing warmer temperatures spread of earlier unknown viruses, such as the Hantavirus in the USA, has been linked to the climate change while in other locations there is an increase in the range of insects carrying diseases like dengue and American Plague. Sudden outbursts of unknown diseases have also been reported in Africa and South America. |
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Asthma
The increase in the number of hot days causes elevation in the smog levels, which in turn exacerbates asthma, bronchitis and other respiratory illnesses leading to a greater number of hospitalizations. |
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Extreme Weather |
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Fierce Hurricanes
Warmer climate heats ocean waters, and warm ocean water fuels hurricanes. Scientists predict that global warming will lead to more intense storms. In 2005 MIT published the research showing hurricane intensity had doubled over the past 30 years and was linked to rising sea surface temperatures caused by global warming.
Heat Waves
The increase in the length and severity of heat waves caused hundred of lives, crop failures, and wild fires in 2006 in USA. The world experienced its deadliest heat wave when Europe was struck in 2003 and a staggering 27,000 people lost their lives. In July 1995, Chicago experienced the unprecedented heat wave in which 739 people perished. |
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Ecosystems |
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Warmer waters, more acidic oceans and stronger storms are taking their combined toll on coral reefs. Loss of coral reefs translates into huge economic losses in coastal regions dependent on reefs—they provide about $375 billion each year in food and tourism income. Severe damage to reefs is also an ecological catastrophe.
While the above dangers represent grave problems, it has been argued that it would benefit society more to carry on with economic business as usual, and simply adapt to the new climatic circumstances. However, in the long term the impact is likely to be on such a scale that adaptation cannot be presented as a preferred option. |
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Can Anything Be Done? |
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Yes! The most important action we can take to slow global warming is to reduce emissions of heat-trapping gases. Governments, individuals, and businesses can all help.
Governments can adopt a range of options for reducing greenhouse gas emissions, including
- increasing energy efficiency standards.
- encouraging the use of renewable energy sources (such as wind and solar power).
- eliminating subsidies that encourage the use of coal and oil by making them artificially cheap.
- protecting and restoring forests, which serve as important storehouses of carbon.
Individuals can reduce the need for fossil fuels and often save money by
- driving less and driving more fuel-efficient and less-polluting cars.
- using energy-efficient appliances.
- insulating homes.
- using less electricity in general.
Businesses can increase efficiency and save substantial sums by doing the same things on a larger scale. And utilities can avoid building expensive new power plants by encouraging and helping customers to adopt efficiency measures |
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Kyoto Protocol |
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The objective of the Kyoto Protocol is to achieve "stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.”
According to the Protocol, countries must reduce total greenhouse gas emissions by 2012, compared to 1990 levels. As of June 2007, 172 countries and government entities have ratified the Kyoto Protocol and have no obligation beyond monitoring and reporting emissions. |
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References |
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http://www.computare.org/Support%20documents/Guests/Douglas%20Lightfoot/Doug%20Lightfoot_07_06.htm
http://www.msnbc.msn.com/id/6662932/
http://fightglobalwarming.com/page.cfm?tagID=273
http://www2.le.ac.uk/ebulletin/features/2000-2009/2004/12/nparticle-vkt-hgf-t4c
http://www.all-about-global-warming.com/
http://www.lenntech.com/greenhouse-effect/global-warming-history.htm
http://www.aip.org/history/climate/summary.htm
http://www.llnl.gov/str/Com1096.html
http://en.wikipedia.org/wiki/Global_warming
http://www.ucsusa.org/global_warming/science/global-warming-faq.html |
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Pictures & Illustrations |
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http://www.plant-a-tree-today.org/plant-a-tree-today-email.asp?Pages=0&MailId=31
http://www.benfieldhrc.org/activities/issues5/dcc.htm
http://green.nationalgeographic.com/environment/global-warming/gw-impacts-interactive.html?nav=FEATURES
http://concise.britannica.com/ebc/art-8569/Svante-Arrhenius-1918
http://www.newscientist.com/blog/environment/2007/05/climate-myths-special.html
http://www.ucsusa.org/global_warming/science/global-warming-faq.html |
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Videos |
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http://fightglobalwarming.com/viewads.cfm?video=train |
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